Azure Service Bus: What's a 'request' and a 'message'?

Question

In Microsoft Azure, under service bus, you can see activity graphs for the different queues/topics etc.

The graph shows various different lines, such as incoming messages, outgoing messages, successful requests etc.

What is a Request? And what is a Message?

Requests seem to be constantly occurring and often significantly large than the number of messages (in topics). Even though the number of servers listening to the queue remains the same - sometimes the number of requests will dramatically increase without seeing any change in the number of messages.

Answer 1

I assume that a request is a poll on a queue / subscription, even if that didn't result in a message being pulled. With the OnMessage message pump model , you typically wait 'forever' until a message arrives, resulting mostly in an equal number of receives & messages. But when your role/thread/pump stops and restarts, that will trigger a new receive, even if no message was found.